Ukraine Reports Dozens Killed In Slovyansk Fighting

Ukraine says its military has killed 30 pro-Russian separatists as government forces try to retake Slovyansk and other cities near the border with Russia. At least four Ukrainian soldiers have died, and separatists shot down a helicopter in eastern Ukraine.

The helicopter's "crew escaped because they apparently crashed into a riverbed once it was shot down," NPR's Soraya Sarhaddi Nelson reports.

Ukraine's Interior Minister Arsen Avakov announced the death toll in Slovyansk on Tuesday.

From Donetsk, about 75 miles to the south of Slovyansk, Jessica Golloher filed this report for our Newscast Desk:

"Ukraine's interior ministry is saying that it is continuing its anti-terrorism campaign to root out pro-Russian demonstrators here in eastern Ukraine, with Arsen Avakov posting on his Facebook page that around 800 demonstrators are using large-caliber weapons and mortars in an attempt to push back Kiev's troops.

"This after gunbattles and explosions could be heard north of Donetsk in the pro-Russian stronghold of Slovyansk. The West and Ukraine say Russia is stoking dissent here. Moscow denies the claims and says Kiev needs to pull its troops back in order for there to be dialogue."

The airport in Donetsk was shut down Tuesday, though officials did not provide a reason. From Kiev, the Ukrainian capital, NPR's Soraya Sarhaddi Nelson spoke about the closure on Morning Edition.

"This probably has to do with the May 9 Victory Day, which is the celebration of the Soviet victory over the Nazis in World War II," Soraya says. "That is expected to drive up more tensions, and they don't want more people showing up to agitate."

In addition to that date, two others are approaching that will surely increase tensions. On May 25, Ukraine will hold presidential elections, and on May 11, separatists plan to hold a referendum to decide whether to break away and join Russia, following the path of Crimea.

As we reported Monday, Ukraine has also "dispatched a special police unit to try to control the deadly clashes in the southern Ukrainian port city of Odessa."